In a violent year in St. Louis, a theme has emerged: The gun used in the crime was probably stolen.

The city is on pace for around 200 homicides in 2015, the most in 20 years. Meanwhile, gun theft reports are up nearly 70 percent. It's not homes or gun stores being targeted: It's cars and trucks.

Many people coming into the city bring guns, but venues such as sports stadiums and theaters prohibit them — so they get left in the car. Police Chief Sam Dotson says criminals know that.

In the St. Louis region, both sales and applications for concealed-carry permits have spiked since the unrest that followed the fatal shooting of Michael Brown last year.

Experts say that with more guns come more gun thefts.